List of Tables xix

Preface xxi

Acknowledgments xxiii

List of Abbreviations xxv

About the Book xxxi

1 Introduction 1

1.1 The Water–Energy Nexus 1

1.2 Systems and Their Properties 4

1.3 Thermodynamic Concentrations, Constants, Units, and Relationships 6

1.3.1 Dimensional Consistency 10

End of Chapter 1 Problems 11

References 12

2 The First Law of Thermodynamics and Energy Balances for Closed Systems 13

2.1 Work and Energy Overview 13

2.2 Internal Energy and the First Law 15

2.3 Expansion Work 19

2.4 Heat Exchange at Constant Volume 22

2.4.1 Special Property of Internal Energy for Ideal Gas 25

2.5 Nonexpansion Work 26

2.5.1 Extension of a Solid 26

2.5.2 Extension of a Surface 26

2.5.3 Rotating Shaft Work 27

2.5.4 Electrical Work 28

2.6 Enthalpy 28

2.6.1 Special Property of Enthalpy for Ideal Gas 32

2.7 Enthalpy versus Internal Energy for Ideal Gas 32

2.8 Special Case for Ideal Gas with Little Volume Change 34

2.9 Relating C P to C V for An Ideal Gas 34

2.10 Adiabatic Changes for Ideal Gas 35

2.11 Standard Enthalpy Changes 37

2.12 Enthalpies of Chemical Change, that is Reactions 40

2.13 Some Other Useful Relationships 42

End of Chapter 2 Problems 42

References 47

3 The First Law of Thermodynamics and Energy Balances for Open Systems 49

3.1 Kinetic and Potential Energies of Moving Water 49

3.2 First Law Applied to Steady Flow Devices 56

3.3 First Law Applied to Unsteady Flow Devices 68

3.4 Major Head Losses in Piping 70

3.4.1 Head Loss in Pipes with Laminar Flow 71

3.4.2 Head Loss in Pipes with Laminar or Turbulent Flow 75

3.5 Minor Head Losses in Piping 80

3.6 Pump and Turbine Energy 81

End of Chapter 3 Problems 86

References 93

4 Second and Third Laws of Thermodynamics, Entropy, and Free Energy 95

4.1 Defining Entropy 95

4.2 Entropy and the Heat Engine 98

4.2.1 Carnot Engine 100

4.2.2 Refrigeration (Heat Engine in Reverse) 104

4.2.3 Irreversible Heat Engines 106

4.3 Clausius Inequality 107

4.4 Examples of Entropy Change for Specific Processes 109

4.4.1 Entropy Change for Pure Substances 109

4.4.2 Entropy Change When Temperature Changes with Heat Transfer 111

4.4.3 Entropy Change of Liquids and Solids 112

4.4.4 Entropy Change of Ideal Gas 113

4.5 Entropy Balances 114

4.6 Helmholtz and Gibbs Energies 120

4.6.1 When Heating at a Constant Volume in the Absence of Nonexpansion Work 121

4.6.2 When Energy Is Transferred as Heat at Constant Pressure, and There Is No Work Other Than Expansion Work 121

4.6.3 Helmholtz Energy 122

4.6.4 Gibbs Energy 123

4.6.5 Other Properties of Gibbs Free Energy 126

End of Chapter 4 Problems 127

References 135

5 Thermodynamics of Simple Mixtures 137

5.1 Chemical Potential 137

5.1.1 The Chemical Potential Has a Wider Significance Than Just Being a Descriptor for the Molar Gibbs Free Energy 138

5.2 Thermodynamics of Mixing for Ideal Gases 139

5.3 Thermodynamics of Mixing for Liquids 142

5.3.1 Activity Coefficients 143

5.4 Application of Thermodynamics of Mixing for Water Desalination 149

5.5 What About When We Have More than One Phase at Equilibrium (No Reaction) 153

5.5.1 Gibbs Phase Rule 154

5.6 What About When We Have Mixtures that Are Reacting in Solution 154

End of Chapter 5 Problems 157

References 161

6 Thermal Distillation 163

6.1 Idealized Distillation Occurring in a Batch Reactor 163

6.1.1 Batch Processes with Heat Recovery 169

6.2 Overview of Multiple Effect and Multistage Flash Distillation 171

6.3 Design of Forward Feed MED System 176

6.3.1 First Effect 177

6.3.2 Second Effect 178

6.3.3 Third Effect 178

6.3.4 Fourth Effect 179

6.3.5 End Condenser 180

6.4 Defining the Performance of Thermal Desalination Systems 186

6.5 Quantifying Entropy Change During Desalination 189

6.5.1 Flashing 190

6.5.2 Flow Through An Expansion Device Without Phase Change 191

6.5.3 Pumping and Compression 193

6.5.4 Isobaric Heat Transfer 194

6.5.5 Thermal Disequilibrium of Discharge Streams 197

6.5.6 Chemical Disequilibrium of Discharge Streams 198

End of Chapter 6 Problems 200

References 214

7 Membrane Desalination 215

7.1 Overview of Water Treatment Using Membranes 215

7.2 Membrane Operational Parameters 221

7.3 Minimum Isothermal Reversible Work of Membrane Separation 228

7.4 Energy Requirements for Desalination Using a Simple One-Stage Reverse Osmosis Module 233

7.5 Energy Requirements for Desalination Using Reverse Osmosis Modules in Series, With or Without Energy Recovery 238

7.6 A More Practical Approach to Design RO Membrane Desalination that Considers the System Pressure Used to Drive Flow 244

7.7 Entropy Losses During Reverse Osmosis 248

7.7.1 Flow Through an Expansion Device Without Phase Change 248

7.7.2 Pumping 248

7.7.3 Chemical Disequilibrium of Discharge Streams 248

End of Chapter 7 Problems 251

References 259

8 Electrodialysis 261

8.1 Overview of Water Treatment Using Electrodialysis 261

8.2 Common Terms and Definitions in Electrodialysis 265

8.3 Thermodynamics of a Reversible Electrodialysis Process 267

8.4 Practical Minimum Energy Consumption for Electrodialysis 271

8.5 Designing a Practical Electrodialysis System 273

8.5.1 Shading Effect 274

8.5.2 Electrical Conductivity 276

8.5.3 Boundary Layer Resistance 276

8.5.4 Donnan Resistance 278

8.5.5 Water Transport 287

8.5.6 Energy Consumption 288

End of Chapter 8 Problems 292

References 298

9 Electrochemical Treatment of Water 301

9.1 Promise of Electrochemistry in Water Treatment 301

9.2 Electrochemical Reactions and Reactors 302

9.3 Anodic Reactions Under Standard Conditions 305

9.4 Cathodic Reactions Under Standard Conditions 305

9.5 Calculating Standard Potentials and Gibbs Free Energy Values for Half Reactions 305

9.6 Full Cell Reactions at Standard Conditions 309

9.7 Full Cell Reactions Under (Standard) Environmental Conditions 312

9.8 Theoretical Current Demand 315

9.9 Actual Current Demand and Current Efficiency 322

9.10 Overpotential and Reaction Kinetics 324

9.11 Energy Consumption for Water Treatment 331

End of Chapter 9 Problems 332

References 336

Appendix A 339

Index 379